1. Field of the Invention
The present invention relates, in general, to a vent system for use in venting containers.
2. Information Disclosure Statement
In containers of liquid, it is a common practice to have a vent in each of the containers so that during the dispensing of the liquid from the container the outside air can enter the container above the liquid to permit the liquid to flow freely from the container and prevent an air lock during such dispensing of the liquid. Typically, in addition to the opening through which the liquid from the container is dispensed, such containers have a threaded opening in which is threadedly received a vent cap or plug when the container is being stored or shipped and which is removed during dispensing of the liquid from the container to allow air to enter the container.
Also, in typical containers for liquids, particularly those containers which contain chemicals and the like and which are returned to the chemical supplier for a refill, it is desirable to have a means for indicating when the container has been tampered with and for preventing unwanted access to the container.
There have heretofore been other vent assemblies for containers, but the prior art vent assemblies of which applicant is aware have certain drawbacks, namely: (1) In the open position the vents allow water into the container. Thus, when it rains, the rain has a direct path into the container, allowing water to enter the container, which contaminates the chemicals in the container. (2) Once the vent is open, if the container tips over, the liquid leaks from the container. (3) When a vent assembly employing a ratchet mechanism to evidence tampering access to the container is used, the container requires special modifications. Also, such ratchet assemblies are not reusable since a part is broken off when the device is unscrewed. Thus, after the tampering has taken place, it is necessary to throw the whole device away. (4) Many prior vents required a wrench to open and close the vent since these prior vents used plastic against plastic or a flat gasket for the sealing portions of the vent. (5) Also, the plugs of many prior devices have a hex head which projects upwardly for turning by a wrench or by one's fingers, but with such plugs the advantages of a low profile are lost.
Applicant has knowledge of the following patents which may relate to the present invention: Samiran, U.S. Pat. No. 2,649,109, issued Aug. 18, 1953; Krapp, U.S. Pat. No. 2,757,944, issued Aug. 7, 1956; Ward, U.S. Pat. No. 2,843,161, issued Jul. 15, 1958; Limandri, U.S. Pat. No. 3,513,887, issued May 26, 1970; Bower, U.S. Pat. No. 3,840,056, issued Oct. 8, 1974; Shields, U.S. Pat. No. 4,502,516, issued Mar. 5, 1985; Chelette, U.S. Pat. No. 4,893,844, issued Jan. 16, 1990; Dunham, U.S. Pat. No. 1,960,532, issued May 29, 1934; and Jacobi, U.S. Pat. No. 4,949,878, issued Aug. 21, 1990.
Samiran discloses a nozzle for fuel servicing systems for aircraft. The sleeve of the nozzle is rotated about ninety degrees to lock the nozzle to the aircraft by a bayonet type joint. Pulling o the trigger of the nozzle operates certain valves and the fuel saturated air is forced out of the aircraft tank by the incoming fuel and returned to the top of the truck tank.
Krapp discloses a self-venting separable coupling. It has means to vent a system containing the female and male coupling without separating them. This is done by raising one of the levers only.
Ward discloses a tank filling nozzle. The tank filling nozzle has an inlet and a vent. A lever is movable to close off the space (i.e., seal) between the nozzle and the tank opening and opens the passageway to the vent.
Limandri discloses an automatic shut-off closed circuit coupling in which fluid connection is established between a nozzle and an adapter in the filling neck of a vehicle. When the connection is made, valves in both the nozzle and adapter are automatically opened. When the tank is filled to the desired level, vacuum is destroyed in the vent line causing shut off of the fuel flow. Separation of the nozzle closes all valves.
Bower discloses an apparatus for filling liquid storage tanks. The vent device has an input opening, a first discharge port, a second discharge port, a vapor adapter, and a closure cap. A flange forces a valve stem to the open position when the closure cap is in a position closing the end of the valve adapter. The vent device provides the means for limiting the amount of liquid which will be filled into a storage tank in order to permit the liquid trapped within any of the lines leading to or from the storage tank, as a result of filling, to drain into the tank after the filling operation has been terminated.
Shields discloses a vented fuel tank filler. The fill coupling, made up of fixed and movable members, respectively, is preferably of the interlocked dry break type. The members are opened by moving a handle. There is a mechanical interlock to prevent opening of the valve elements until the elements are connected and the mechanical interlock is rotated by a slight relative rotation of the coupling elements. There are guide rods to insure alignment of the couplings. The vent coupling is made up of members of the two way socket and plug type. Advancement of the parts opens the vent valves, then a slight turn of the supply line and attached movable fill coupling releases the interlock. The only turning movement of the valve members is to release the interlock. The handle causes the valve members to move towards one another.
Chelette discloses a tubular coupling with a ventable seal. The tubular coupling forms a self-energizing seal between two tubular members with the seal engaging in response to pressure from a primary direction while venting to pressure from a secondary direction, thereby maintaining the integrity of the metal-to-metal seal and thread annulus.
Dunham discloses a nonrefilling device for liquid containers. After the container has been filled, a plug is threaded in place and welded. There is a check valve mounted within the valve body and an air vent passage which is opened when the check valve is opened, allowing air inflow into the container from the outside air when liquid is withdrawn from the container.
Jacobi discloses a reusable container system. The top wall of the container has a pair of openings therein, one of which constitutes a port through which liquid may be removed from the container and the other constituting a port through which liquid may be delivered to the container, the latter port also functioning as a vent for venting the container as it is filled and emptied. There are tamper-evident means provided in the closures of the two ports for detecting any unauthorized attempts to refill the container.
Also, applicant has knowledge of a two page advertisement of Centryco, Inc. illustrating a CENTRY VENT III automatic safety valve which may be relevant to the present invention and which discloses a vent valve that operates to relieve the vacuum when fluid is withdrawn from the drum. Atmospheric pressure against a disc in the valve compresses a light spring and opens internal ports to break the vacuum.
In addition, applicant has knowledge of a two page advertisement of Justrite Manufacturing Company illustrating various drum vents which may be relevant to the present invention and which discloses a non-metallic dual action drum vent, a brass dual action drum vent, and an end of drum bung vent. Each of the vents are provided with a pressure relief, and with a vacuum relief for "assuring even flow during dispensing operations".